What Would Happen If Every Human on Earth Died?

Let's cross our fingers and hope that we never experience this, but what would happen if every human on the planet was eradicated?

This video by Earth Unplugged ponders that exact question. From head lice losing their source of nutrition to cities crumbling and rivers overflowing, a lack of human presence would have some pretty major effects on the surface of the planet. But try as we might, the lingering evidence of human kind will persist forever—even if it is only radio waves floating through space. [Earth Unplugged]